JP2001320383A - Radio communications equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide radio communications equipment operable in either of the network of a fixed period mode for sending a time reference signal in a fixed period and the network of a nonfixed period mode where the sending timing of the time reference signal is varied. SOLUTION: When a beacon period monitoring part (1314) confirms that a beacon period is fixed when the radio communication equipment operating in a normal nonfixed period mode enters the area of the fixed period mode with movement, a switch (1309) is connected to a fixed period mode processing part (1312), to start a transmission propriety deciding part (1303) and a transmission data dividing part (1313) to partially divide transmission data at need to perform the acquiring trial of a transmission authority.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication apparatus for communicating data between a plurality of wireless terminals, and more particularly, to efficiently transmitting isochronous data such as moving images and audio and asynchronous data such as file access. To a wireless communication device.

[0002]

2. Description of the Related Art Conventionally, for a wireless local area network composed of a plurality of terminals, a method of performing packet-type wireless communication, a method of performing ATM-type wireless communication, and the like have been studied. For example, IEEE Std 802.11
The data transmission method described in -1997 is a packet-type communication method, and a terminal transmitting data determines whether or not the wireless medium is unused for a certain period of time, and transmits a signal when the wireless medium is unused. CSMA / that can send
The CA (Carrier Sense Multiple Access With Region Avoidance) method is used, and is an access method suitable for asynchronous data communication such as file transfer and electronic mail.

FIG. 18 shows access by CSMA / CA used in IEEE 802.11. The wireless communication device owning the transmission data is a DIF
If it is confirmed by monitoring the presence / absence of a signal that the wireless medium is unused for a period called S, the wireless medium waits for a random slot.

[0004] If no signal appears in the wireless medium during this time, the data is transmitted assuming that the transmission right has been acquired. If the transmitted data is destined for only one particular wireless communication device, the receiving wireless device
ACK is immediately transmitted to the transmission data transmitting station at a time interval shorter than DIFS.

[0005] During this time, in order to reduce the probability that the third station transmits a signal to the wireless medium, the transmission data includes
The total time of the data transmission time, SIFS, and ACK transmission time is stored as NAV. NAV indicates that the wireless medium is busy during that period. When broadcasting data to a plurality of wireless communication devices, an ACK from the destination is not requested, and thus the SIFS and ACK are not included in the NAV. As described above, the access method that gives an access right to a specific wireless communication device when necessary is suitable for asynchronous data that does not require real-time properties such as file access and electronic mail.

FIG. 19 shows a basic access cycle. In the figure, reference numeral 1901 denotes a beacon signal indicating the beginning of one access cycle, and 1902 denotes a period during which data can be transmitted in one access cycle.
In IEEE 802.11, a beacon may not be able to be transmitted on a regular basis because a wireless communication device that has acquired a transmission right by the CSMA / CA transmits data immediately before the end of an access cycle. In this case, there is a function of maintaining the cycle synchronization by storing the delay from the regular time in the next beacon signal.

[0007]

However, with the recent development of multimedia elemental technology, large volumes of video information and the like have flowed in real time over a network, and a certain amount of data has arrived within a certain time. There is an increasing demand for guaranteed isochronous data communication. Therefore, a method for reliably performing data communication with less overhead within a limited frequency is required.

For such data, a time division multiple access system in which a specific band is allocated in advance at a specific time is suitable. Therefore, an access method suitable for isochronous data and an access method suitable for asynchronous data communication are applied in a time-division manner. However, when the CSMA / CA method is adopted, when the beacon signal fluctuates as described above, Occurs, it is necessary to normally receive a beacon signal every time in order to synchronize the network, and in a radio propagation environment that changes every moment, there may be cases where normal reception of a beacon signal is not performed. As described above, the time used as a reference for the access method in which the access right is granted at a fixed time is not determined, and the first is that the line use efficiency is greatly reduced.
Issues.

[0009] In an environment where video data such as television and video is often distributed at home, a wireless communication device suitable for isochronous data transmission, an environment mainly dealing with asynchronous data such as a school or office, etc. Although a system is constructed using wireless devices suitable for asynchronous data transmission, there is a second problem that a wireless communication device used at home cannot be taken out to a school and used because the systems are different.

In order to solve the first problem, the present invention prevents transmission of the next beacon signal from being interrupted by data transmission when transmission data for communication in the CSMA / CA area occurs. , Continue to establish network synchronization.
It is another object of the present invention to provide a wireless communication system device for effectively using the remaining CSMA / CA area.

In order to solve the second problem, the present invention uses a fixed period mode for using an access method suitable for isochronous data transmission or an access method for asynchronous data transmission. Therefore, an object of the present invention is to provide a wireless communication device that operates by selecting the non-fixed period mode.

[0012]

In order to solve the above-mentioned first problem, the present invention provides a beacon period information and a time period which can be obtained from a beacon signal when data to be transmitted occurs in a CSMA / CA area. From the divided bandwidth allocation total information, calculate the actual time until the next beacon is transmitted, determine whether the transmission attempt of the data to be transmitted owned by the own terminal is within the remaining time, If it does not fit, do not start the attempt to acquire the right to transmit data, or split the transmission data so that transmission of some of the transmission data is completed before the next beacon transmission It was done.

[0013] This makes it possible to prevent a transmission delay of a beacon signal providing a time reference, and to allocate an isochronous data area based on an absolute time from the beacon signal. Even when the beacon signal cannot be received due to the deterioration of the environment, the transmission timing of the isochronous data can be estimated and transmitted, and the effect of preventing a significant reduction in the specification efficiency of the wireless medium can be obtained. Also,
Even when the CSMA / CA area for transmitting data is not sufficient, it is possible to perform an effective communication.

[0014] In order to solve the second problem, the present invention is directed to a fixed-period operation environment in which a switch when a wireless communication apparatus starts up or a type and a cycle of a beacon signal received while the wireless communication apparatus is operating operate. In this configuration, the mode is switched by determining whether the mode is the non-fixed period mode.

[0015] Thus, the wireless communication device can be used in a mode suitable for the usage environment, and the wireless communication device operating in the non-fixed period mode moves into the system operating in the fixed period mode. However, it is possible to operate in a fixed period mode system without causing interference in the system, and it is possible to efficiently use a wireless medium according to characteristics of data traffic mainly occurring in the system. The effect is obtained.

[0016]

According to the first aspect of the present invention, a beacon period determining unit for estimating a period of a beacon, and until a next beacon is received based on the beacon period estimated by the beacon period determining unit. A remaining time calculation unit that counts the time of the data, and determines whether data transmission is completed within the time calculated by the remaining time calculation unit, and performs a transmission right acquisition trial only when it is determined that the data transmission is completed. It is a wireless communication device characterized by having a transmission permission / inhibition determining unit that determines that the transmission trial of the transmission data owned by estimating the period of the beacon is performed by the next beacon reception prediction time. Since it is determined whether or not to end the transmission and whether or not to make a transmission attempt, interference with the beacon can be avoided, and the accuracy of beacon reception in the network is improved. Having.

According to a second aspect of the present invention, a beacon period determining unit for estimating a beacon period, and counting a time until a next beacon is received based on the beacon period estimated by the beacon period determining unit. A remaining time calculation unit, a transmission availability determination unit that determines whether data transmission is completed within the time calculated by the remaining time calculation unit, and a transmission availability determination unit that determines that the transmission is not completed. A wireless communication device having a transmission data dividing unit that divides transmission data into an amount of data that can be transmitted before receiving the next beacon, and owns by estimating a period of the beacon. Since the transmission attempt is performed with the data partially divided so that the transmission attempt of the transmission data is completed by the next expected beacon arrival time, interference with the beacon can be avoided, and It has a effect that the accuracy of the beacon reception is improved in over click, the effect that use efficiency is improved in the radio channel.

According to a third aspect of the present invention, in a case where communication of isochronous data and asynchronous data is performed alternately, a beacon period determining unit for estimating a beacon period and a beacon estimated by the beacon period determining unit are provided. A remaining time calculation unit that counts the time until the next beacon is received, a TDMA calculation unit that determines the lapse of the isochronous data communication period from the beacon, and an isochronous calculation from the TDMA calculation unit. After knowing that the data communication period has elapsed, it is determined whether or not the transmission of the asynchronous data is completed within the time calculated by the remaining time calculation unit. A wireless communication device characterized by having a transmission permission / inhibition decision unit for deciding to perform transmission of asynchronous data by the next predicted beacon arrival time. If the transmission is not completed, it is possible to prevent the asynchronous data from becoming an interference wave of the beacon by not performing the transmission right acquisition attempt, thereby improving the accuracy of the beacon reception in the network and the effect of transmitting the asynchronous data. This has the effect of preventing transmission delay of isochronous data.

According to a fourth aspect of the present invention, in the case where communication of isochronous data and asynchronous data is performed alternately, a beacon period determining unit for estimating a beacon period, and a beacon estimated by the beacon period determining unit. A remaining time calculation unit that counts the time until the next beacon is received, a TDMA calculation unit that determines the lapse of the isochronous data communication period from the beacon, and an isochronous calculation from the TDMA calculation unit. After knowing that the data communication period has elapsed, the transmission permission / inhibition determining unit that determines whether the transmission of the asynchronous data is completed within the time calculated by the remaining time calculation unit, and the transmission permission / inhibition determination unit is completed. A wireless communication device having a transmission data division unit for dividing transmission data into an amount of data that can be transmitted until the next beacon is received when it is determined that the transmission is not performed Yes, the asynchronous data becomes an interference wave of the beacon by performing a trial of acquiring the transmission right by dividing a part of the asynchronous data so that the data transmission attempt of the asynchronous data is completed by the next expected beacon reception time. The effect of improving the accuracy of beacon reception in the network, the effect of preventing the transmission delay of isochronous data due to the transmission of asynchronous data, and the effect of improving the specification efficiency of the wireless medium Having.

According to a fifth aspect of the present invention, there is provided a fixed-period mode processor for controlling data transmission so as not to hinder transmission of a beacon, and a non-periodic mode controller for performing signal transmission without considering a beacon period. A fixed-cycle mode processing unit, wherein the wireless communication device having a manual switch for switching between the fixed-cycle mode processing unit and the non-fixed-cycle mode processing unit, the beacon periodically It has the effect that it can be used in both the arriving network and the network that fluctuates in the arrival of the beacon.

According to a sixth aspect of the present invention, the switch according to the fifth aspect determines whether or not the rising edge of the beacon is detected at the same time interval, so that the fixed cycle mode processing unit and the fixed cycle mode processing unit are not fixed. 6. A mode switching unit for automatically switching to a periodic mode processing unit.
It is a wireless communication device as described, and it is possible to automatically switch between fixed period mode and non-fixed period mode by monitoring the beacon reception interval, and the beacon arrives periodically without the user's awareness The present invention has an effect that the present invention can be used in both a network that performs the communication and a network that fluctuates in the arrival of the beacon.

According to a seventh aspect of the present invention, the mode switching unit according to the sixth aspect automatically switches the fixed period mode processing unit and the non-fixed period mode processing unit based on the operation mode information transmitted from the center station. 7. The wireless communication apparatus according to claim 6, wherein the mode is switched by determining whether the mode is the fixed cycle mode or the non-fixed cycle mode during an authentication procedure for connecting to a wireless communication apparatus that gives a beacon. The beacon can be used in both a network where beacons arrive periodically and a network which fluctuates in the arrival of beacons without the user's awareness.

According to an eighth aspect of the present invention, the mode switching unit according to the sixth aspect detects the operation mode information added to the received data and compares the table with a table, so that the mode switching unit and the fixed-period mode processing unit are compared. The wireless communication device according to claim 6, wherein the wireless communication device automatically switches to the fixed cycle mode processing unit, and can determine and switch between the fixed cycle mode and the non-fixed cycle mode from a signal other than the beacon,
It has the effect that it can be used in both networks where beacons arrive periodically and networks that fluctuate in arrival of beacons without the user's awareness.

An embodiment of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIGS. 1 to 3 show an embodiment of a wireless communication apparatus according to the present invention.

FIG. 1 is a block diagram showing the configuration of the wireless communication apparatus. This wireless device is a beacon period determination unit (10
1), remaining time calculation unit (102), transmission availability determination unit (1)
03), a transmission / reception unit (104), a reception processing unit (105),
It comprises a reception buffer (106), a transmission buffer (107), and a host (108). FIG. 2 is a flowchart when data is transmitted in the CSMA / CA mode, and FIG. 3 is a flowchart until the beacon period is determined. Hereinafter, the operation of the wireless communication apparatus described in the present embodiment will be described based on the flowchart of FIG.

When the power is turned on, the wireless communication apparatus receives a beacon signal indicating the start of a fixed cycle a plurality of times, and determines a beacon cycle by a beacon cycle calculation unit (101) that measures the interval between beacon signals (S201).

As a method of determining the beacon period, in the present embodiment, when a beacon is received twice in the same period as shown in the flowchart of FIG. 3, the period is determined as the beacon period (S301 to S304).

[0029] The wireless communication terminal includes a remaining time calculator (102).
In step S203, a timer is started (S203), and the time until the next beacon signal is received is counted down to calculate the actual time that can be used within the beacon period. When transmission data is generated in the wireless communication terminal (S205), it is determined whether or not the remaining time is shorter than the header length, that is, whether or not there is room to transmit information (S20).
6) If there is no room, the process shifts to beacon reception wait. If there is room, the actual data for transmitting the transmission data based on the interframe space DIFS until the start of transmission, the backoff, the transmission data length, and the transmission speed. Time is calculated (S207).

When the transmission data is unicast data,
To request an ACK, the real time it takes to send the ACK and the interframe space S for the ACK transmission
The time obtained by adding the IFS to the time calculated in S207 is calculated as the actual transmission trial time by the transmission permission / inhibition determining unit (103) (S209). On the other hand, if the transmission data is multicast data, the ACK transmission time and the ACK transmission interframe space SIFS are not added (S
210).

The transmission permission / inhibition decision section (103) further compares the actual transmission trial time with the remaining time, and if the remaining time is longer, attempts to acquire the transmission right by CSMA / CA in order to obtain the transmission right. (S212). If the remaining time is shorter, the transfer to the reception mode is performed without performing the transfer attempt in the corresponding beacon period.

According to the present embodiment, even when the beacon period information is not stored in the beacon signal, the beacon signal period can be determined. Can be avoided.

(Embodiment 2) FIGS. 4 and 5 show an embodiment of a wireless communication apparatus according to the present invention.

FIG. 4 is a block diagram showing the configuration of the wireless communication device. The wireless device is a beacon period extracting unit (4
01), remaining time calculation section (402), transmission permission / inhibition determination section (403), transmission / reception section (404), reception processing section (40)
5), reception buffer (406), transmission buffer (40)
7) and a host (408).

FIG. 5 is a flowchart for transmitting data in the CSMA / CA mode. Hereinafter, FIG.
The operation of the wireless communication apparatus described in the present embodiment will be described based on the flowchart of FIG.

When turning on the power, the radio communication apparatus receives a beacon signal indicating the start of a fixed cycle, and extracts a beacon cycle from cycle information stored in the received beacon signal (S501, S502). The wireless communication terminal starts a timer in the remaining time calculation unit (402) (S503),
By counting down the time until the next beacon signal is received, the actual time that can be used within the beacon period is calculated. When transmission data is generated in the wireless communication terminal (S505), it is determined whether or not the remaining time is shorter than the header length, that is, whether or not there is enough time to transmit information (S506). The process shifts to beacon reception waiting, and if there is room, the interframe space DIFS up to the start of transmission and the actual time required for transmitting the transmission data are calculated based on the backoff, the transmission data length, and the transmission speed (S507). .

When the transmission data is unicast data,
To request an ACK, the real time it takes to send the ACK and the interframe space S for the ACK transmission
A time obtained by adding the IFS to the time calculated in S507 is calculated as an actual transmission trial time by the transmission permission / inhibition determining unit (403) (S509). On the other hand, when the transmission data is multicast data, the ACK transmission time and the ACK transmission interframe space SIFS are not added (S
510).

The transmission permission / inhibition decision section (403) further compares the actual transmission trial time with the remaining time (S51).
1) If the remaining time is longer, C
Attempt to acquire transmission right by SMA / CA (S51
2). If the remaining time is shorter, the transfer attempt in the corresponding beacon period is stopped, and the mode shifts to the reception mode.

According to the present embodiment, it is possible to avoid interference with a beacon signal by a wireless device having transmission data.

(Embodiment 3) FIGS. 6 and 7 show an embodiment of a wireless communication apparatus according to the present invention.

FIG. 6 is a block diagram showing the configuration of the wireless communication device. This wireless device is a beacon period determination unit (6
01), remaining time calculation unit (602), transmission permission / inhibition determination unit (603), transmission data division unit (604), reception processing unit (605), reception buffer (606), transmission buffer (607), host (608) , A transmission / reception unit (609). FIG. 7 shows a flowchart when data is transmitted in the CSMA / CA mode. Hereinafter, the operation of the wireless communication apparatus described in the present embodiment will be described based on the flowchart of FIG.

When the beacon signal does not contain beacon period information after power-on, the wireless communication apparatus operates in the same manner as in the first embodiment. The beacon period is determined in the same manner.

The wireless communication terminal receives the beacon (S7)
01) and a timer is started in the remaining time calculation unit (S7).
02) The actual time that can be used within the corresponding beacon period is calculated by counting down the time until the next beacon signal is received. When transmission data is generated in the wireless communication terminal (S704), it is determined whether or not the remaining time is shorter than the header length, that is, whether or not there is enough time to transmit information (S705). The process shifts to waiting for beacon reception, and if there is room, the actual time required for transmitting the transmission data is calculated based on the interframe space DIFS until the start of transmission and the backoff, the transmission data length, and the transmission speed (S706). .

When the transmission data is unicast data,
To request an ACK, the real time it takes to send the ACK and the interframe space S for the ACK transmission
The time obtained by adding the IFS to the time calculated in S706 is calculated as the actual transmission trial time by the transmission permission / inhibition determining unit (603) (S708). On the other hand, when the transmission data is multicast data, the ACK transmission time and the ACK transmission interframe space SIFS are not added (S
709).

The transmission permission / inhibition decision section (603) further compares the actual transmission trial time with the remaining time (S71).
0), if the remaining time is longer, C
Attempt to acquire transmission right by SMA / CA (S71)
3). If the remaining time is shorter, the transmission data is divided into a size that allows transmission within the corresponding beacon period (S711), and an attempt is made to acquire a transmission right (S713).
However, in this case, the NAV is set only for the transfer trial of the divided first data (S712, transmission data + ACK + SIFS for unicast, only transmission data for multicast), thereby avoiding continuous transmission of fragments. . On the receiving side, the separately received data is linked by the sequence number and decoded.

According to the present embodiment, it is possible to avoid interference with a beacon signal by a wireless device having transmission data, and to use a wireless medium more effectively.

(Embodiment 4) FIGS. 8, 9 and 14 show an embodiment of the radio communication apparatus according to the present invention.

The wireless communication apparatus is capable of transmitting data by a plurality of access methods. As shown in FIG.
The MA unit (141) and the CSMA / CA unit (142) are alternately repeated. FIG. 8 is a block diagram showing a configuration of the wireless communication device according to the present embodiment.

The present wireless device is provided with a beacon period determination unit (80
1) and a CSMA / CSM including a remaining time calculation unit (802), a transmission permission / inhibition determination unit (803), and a reception processing unit (805).
A CA control unit (812), a transmission / reception unit (804), a reception buffer (806), a transmission buffer (807), a host (808), a switching unit (809) for switching an access method, and a TDMA calculation unit ( TDM containing 810)
A control unit (811). Figure 9 shows CSMA / CA
5 shows a flowchart for transmitting data in a mode. Hereinafter, the operation of the wireless communication apparatus described in the present embodiment will be described based on the flowchart of FIG.

When the beacon signal contains no beacon period information after the power is turned on, the wireless communication apparatus operates in the same manner as in the first embodiment. The beacon period is determined in the same manner. The beacon signal stores TDMA slot allocation information within the beacon period, and indicates which time slot is used by which wireless terminal. The wireless communication terminal receives the beacon (S90
1) and the total amount of the TDMA period obtainable from the beacon signal is calculated by the TDMA calculation unit (S902).
At the same time, the timer is started in the remaining time calculation unit (802) (S903), and the time until the next beacon signal is received is counted down, thereby calculating the actual time that can be used within the beacon period.

When the TDMA period has elapsed after the reception of the beacon (S904), the TDMA calculation unit (810) inputs a signal for permitting the CSMA / CA mode to the transmission permission / inhibition determination unit (803) (S906). During the TDMA period, TDMA processing is performed.
Even if transmission data occurs in the CA, the access right acquisition operation is not performed and the operation is delayed until the end of the TDMA period (S
905).

After the end of the TDMA period, when transmission data is generated in the radio communication terminal (S908), it is determined whether or not the remaining time is shorter than the header length, that is, whether or not there is enough time to transmit information (step S908). S909) If there is no room, the process shifts to beacon reception waiting. If there is room, the interframe space DIFS until the start of transmission is set.
The actual time for transmitting the transmission data is calculated based on the back-off, the transmission data length, and the transmission speed (S9).
10).

When the transmission data is unicast data,
To request an ACK, the real time it takes to send the ACK and the interframe space S for the ACK transmission
The time obtained by adding the IFS to the time calculated in S910 is calculated as the actual transmission trial time by the transmission permission / inhibition determining unit (803) (S912). On the other hand, when the transmission data is multicast data, the ACK transmission time and the ACK transmission interframe space SIFS are not added (S
913).

In the transmission permission / inhibition decision unit (803), the CSMA
Under the condition that the signal for permitting the / CA mode is input, the magnitude of the actual transmission trial time is compared with the remaining time (S914). Attempt to acquire the transmission right by the CA (S915). If the remaining time is shorter, the transfer attempt in the corresponding beacon period is stopped, and the mode shifts to the reception mode.

According to the present embodiment, TDMA and CSMA
A wireless communication device that can operate in both the
When possessing data to be transmitted by CA, it is possible to avoid interference with the beacon signal by the wireless communication device.

(Embodiment 5) FIGS. 10 and 11 show an embodiment of the radio communication apparatus according to the present invention.

FIG. 10 is a block diagram showing the configuration of the wireless communication device. This wireless device is a CSMA / CA control unit including a beacon period determination unit (1001), a remaining time calculation unit (1002), a transmission permission / inhibition determination unit (1003), a reception processing unit (1005), and a transmission data division unit (1013). (1012), a transmission / reception unit (1004), a reception buffer (1006), a transmission buffer (1007), a host (1008), a switching unit (1009) for switching an access method, and a TDMA calculation unit (1010). Including T
And a DMA controller (1011).

FIG. 11 is a flowchart for transmitting data in the CSMA / CA mode. Hereinafter, the operation of the wireless communication apparatus described in the present embodiment will be described based on the flowchart of FIG.

When the beacon signal contains no beacon period information after the power is turned on, the wireless communication apparatus operates in the same manner as in the first embodiment. The beacon period is determined in the same manner. The beacon signal stores TDMA slot allocation information within the beacon period, and indicates which time slot is used by which wireless terminal.

The wireless communication terminal receives the beacon (S1)
101) and the TDM obtained from the beacon signal
The total amount of the period A is calculated by the TDMA calculation unit (S11).
Along with 02), a timer is started in the remaining time calculation unit (S1103), and the time until the next beacon signal is received is counted down, thereby calculating the actual time that can be used within the corresponding beacon period.

After receiving the beacon, the TDMA calculation unit
When the period A has elapsed (S1104), a signal for permitting the CSMA / CA mode is input to the transmission permission / inhibition decision unit (1003) (S1106), and the TDM
During the period A, the TDMA process is executed.
Even if transmission data occurs in the SMA / CA, the access right acquisition operation is not performed, and the operation is delayed until the TDMA period ends (S1105).

When transmission data is generated in the wireless communication terminal after the end of the TDMA period (S1108), it is determined whether or not the remaining time is shorter than the header length, that is, whether or not there is enough time to transmit information (step S1108). S1109) If there is no room, the process shifts to waiting for beacon reception, and if there is room, the interframe space DIFS until the start of transmission
And the actual time for transmitting the transmission data is calculated based on the backoff, the transmission data length, and the transmission speed (S1110).

When the transmission data is unicast data,
To request an ACK, the real time it takes to send the ACK and the interframe space S for the ACK transmission
The time obtained by adding the IFS is calculated as the actual transmission trial time by the transmission permission / inhibition determining unit (S1112).

On the other hand, if the transmission data is multicast data, the ACK transmission time and the ACK transmission interframe space SIFS are not added (S1113).

In the transmission permission / inhibition decision unit (1003), the CSM
Under the condition that the signal for permitting the A / CA mode is input, the actual transmission trial time is compared with the remaining time (S1114). If the remaining time is longer, the CSMA is performed to obtain the transmission right. Attempt to acquire the transmission right by / CA (S1115). If the residence time is smaller,
The transmission data is divided into a size that allows transmission within the beacon period (S1116), and the transmission right is acquired (S1115).

However, in this case, the NAV is set only for the transfer trial of the divided first data (S1117,
By transmitting data + ACK + SIFS in unicast and transmitting data only in multicast), it is possible to avoid transmitting fragments continuously.

On the receiving side, the separately received data is linked by the sequence number and decoded.

According to the present embodiment, TDMA and CSMA
A wireless communication device that can operate in both the
When possessing data to be transmitted by the CA, it is possible to avoid interference with the beacon signal by the wireless communication device and to use the wireless medium more effectively. In the fourth and fifth embodiments, TDMA
However, the same applies to the case where a circuit switching method such as DECT or a polling method is used.

(Embodiment 6) FIG. 12 shows an embodiment of the radio communication apparatus according to the present invention.

The wireless communication apparatus includes a manual mode changeover switch (1209) and a beacon period determination section (120).
1) A fixed period mode processing unit (1212) including a remaining time calculation unit (1202), a transmission availability determination unit (1203), a transmission data division unit (1213), a reception processing unit (1205), and a transmission processing unit (1210) A non-fixed-period mode processing unit including a transmission processing unit and a reception processing unit (1211);
A transmission / reception unit (1204) and a reception data buffer (120
6), a transmission data buffer (1207), and a host (1208).

When the manual switch (1209) is connected to the non-fixed period mode processing unit, the beacon period determination unit (1201), the remaining time calculation unit (1202), the transmission availability determination unit (1203), the transmission data Division unit (121
The power supply to 3) is omitted, and the non-fixed periodic processing unit (12
Only 11) operates.

On the other hand, when the manual switch (1209) is connected to the fixed cycle mode, the beacon cycle determination unit (120) required to operate in the fixed cycle mode is used.
1) The first embodiment in which the remaining time calculation unit (1202), the transmission permission / non-permission determination unit (1203), and the transmission data division unit (1213) are activated and do not hinder transmission at a fixed period.
It operates in the manner shown in FIGS.

According to the present embodiment, the wireless communication apparatus can participate in a network as a network system terminal operating at a non-fixed cycle or as a network system terminal operating at a fixed cycle.

(Embodiment 7) FIG. 13 shows an embodiment of the radio communication apparatus according to the present invention.

The wireless communication apparatus is provided with a beacon monitor (131)
4) a mode switching unit (1315) including a mode selection unit (1316) and a mode switching switch (1309), a beacon period determination unit (1301), and a remaining time calculation unit (13)
02), a fixed-period mode processing unit (131) including a transmission permission / inhibition determination unit (1303), a transmission data division unit (1313), a reception processing unit (1305), and a transmission processing unit (1310).
2), a transmission processing unit (1310), and a reception processing unit (130)
5) a non-fixed period mode processing unit (1311),
A transmission / reception unit (1304) and a reception data buffer (130
6), a transmission data buffer (1307), and a host (1308).

When a beacon signal is received a plurality of times at a fixed cycle from the same radio communication apparatus, the switch is sent to the fixed cycle mode processing unit (1312) operating under the fixed cycle beacon described in the first to fifth embodiments. When the connection is detected and the fluctuation of the beacon period is detected, the switch is connected to the non-fixed period mode processing unit (1311).

For example, the trigger is set to five times, and when beacon reception is completed, a pulse is input to the beacon reception instruction signal indicating beacon reception. The beacon monitoring unit (1314) monitors the rising edge of the pulse and automatically detects the rising edge at the same time interval while detecting the pulse five times, and automatically connects the switch to the fixed period mode processing unit. I do.

If a large fluctuation occurs in the rise of the beacon reception instruction signal during the detection of this pulse five times, the switch is automatically connected to the non-fixed period mode processing unit (1311). When the switch is connected to the non-fixed period mode processing unit (1311), the beacon period determination unit (1301), the remaining time calculation unit (1302), the transmission availability determination unit (1303), and the transmission data division unit (131)
The power supply to 3) is omitted, and the non-fixed period processing unit (13)
Only 11) operates.

When the switch is in the fixed cycle mode processing section (131)
In the case of connection to 2), the beacon period determination unit (1301), the remaining time calculation unit (1302), and the transmission availability determination unit (130) required to operate in the fixed period mode
3) The transmission data division unit (1313) is activated, and operates in the manner described in the first to fifth embodiments so as not to hinder transmission at a fixed period.

According to the present embodiment, the wireless communication apparatus can be used as a network system terminal that operates at a non-fixed cycle without the user being aware of the form of the network, and as a network system terminal that operates at a fixed cycle. You can automatically switch to the appropriate method to participate.

(Embodiment 8) FIGS. 15 and 16 show an embodiment of the radio communication apparatus according to the present invention.

FIG. 15 is a block diagram showing the configuration of the wireless communication device. The wireless device is a transmitting / receiving unit (1501)
Authentication control unit (1503), mode selection unit (1503)
4), a mode switching unit (1) comprising a switch (1505)
502), a fixed cycle mode processing unit (1506), a non-fixed cycle mode processing unit (1507), a reception data buffer (1508), a transmission data buffer (1509), and a host (1508).

FIG. 16 is a sequence diagram for determining the operation mode. A wireless communication device that gives a time reference on the network system is called a center station, and a wireless communication device that operates according to a beacon signal from the center station is called a communication station. A communication station newly entering a network needs to make an authentication request to the center station in order to connect to the network.

The communication station monitors the wireless medium for a certain period (S1601), estimates the reception interval of the beacon signal (S1602), and acquires the transmission right of the authentication request packet by CSMA / CA (S1603). Upon receiving the authentication request packet (S1604), the center station transmits an authentication permission packet to which the operation mode information of the fixed cycle mode or the non-fixed cycle mode is added to the communication station as a response to the authentication request packet (S1605). ). The communication station that has received the authentication permission packet selects an operation mode according to the operation mode information stored in the authentication permission packet, and automatically connects and operates the switch to the processing unit in a suitable mode.

According to the present embodiment, even when period information or operation mode information is not stored in a beacon signal, a network system terminal that operates at a non-fixed period or a network system terminal that operates at a fixed period It is possible to automatically switch to a method suitable for the network and participate.

(Embodiment 9) FIG. 17 shows an embodiment of a wireless communication apparatus according to the present invention.

FIG. 17 is a block diagram showing the configuration of the wireless communication device. The wireless device includes a transmission / reception unit (1701), a preamble verification unit (1703), and a mode selection unit (170).
4), switch (1705), comparison table (171)
1), a fixed cycle mode processing section (1706), and a non-fixed cycle mode processing section (1706).
707), a reception data buffer (1708), a transmission data buffer (1709), and a host (1708).

At the head of the data transmitted in the wireless medium,
The preamble for synchronizing the signal is denoted by code A for the non-fixed period mode and code B for the fixed period mode. Code sequences having the same preamble length are separately prepared for each.

In the wireless communication apparatus, when receiving the transmission data transmitted in the wireless medium, the preamble part is extracted by the preamble verification part, and the preamble part is compared with the comparison table 1 and the comparison table 2, respectively. The mode shown in the table is selected, and switches are automatically connected to the processing units corresponding to each mode.

When the radio communication apparatus transmits a signal, the preamble of the code in the currently operating mode is added to the head and the data is transmitted.

According to the present embodiment, when the period information or the operation mode information is not stored in the beacon signal, or before the beacon signal is received from the center station, the operation mode is selected and the operation is performed at the non-fixed period. As a network system terminal that operates, and as a terminal of a network system that operates at a fixed cycle, it is possible to automatically switch to a system suitable for the network and participate.

[0092]

As described above, according to the present invention, even in an access method suitable for asynchronous data communication, it is possible to transmit a beacon signal for synchronizing a network at a constant period, as in TDMA. It is easy to realize a mixture of access methods that require synchronization, and it is possible to efficiently achieve both isochronous data communication such as large-capacity image information and asynchronous data communication such as e-mail and file access. An advantageous effect is obtained. Further, according to the present invention, data communication by CSMA / CA can be effectively performed even immediately before a beacon signal, and an advantageous result that the line use efficiency increases can be obtained.

Further, the present invention makes it possible to switch between the fixed cycle mode and the non-fixed cycle mode. The environment where asynchronous data traffic mainly occurs, such as an office or a school, and the isochronous data mainly such as a home. An advantageous effect is obtained in that the mode of the wireless communication device can be efficiently switched in an environment where traffic occurs.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a wireless device according to Embodiment 1 of the present invention.

FIG. 2 is a flowchart showing processing up to activation of a transmission right acquisition trial according to the first embodiment of the present invention;

FIG. 3 is a flowchart showing beacon signal cycle estimation according to the first embodiment of the present invention;

FIG. 4 is a block diagram showing a configuration of a wireless device according to Embodiment 2 of the present invention.

FIG. 5 is a flowchart showing processing up to activation of a transmission right acquisition trial according to the second embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a wireless device according to Embodiment 3 of the present invention.

FIG. 7 is a flowchart showing processing up to activation of a transmission right acquisition trial according to the third embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a wireless device according to Embodiment 4 of the present invention.

FIG. 9 is a flowchart showing processing up to activation of a transmission right acquisition trial according to the fourth embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of a wireless device according to Embodiment 5 of the present invention.

FIG. 11 is a flowchart showing processing up to activation of a transmission right acquisition trial according to the fifth embodiment of the present invention.

FIG. 12 is a block diagram showing a configuration of a wireless device according to Embodiment 6 of the present invention.

FIG. 13 is a block diagram showing a configuration of a wireless device according to Embodiment 7 of the present invention.

FIG. 14 is an explanatory diagram showing a method of accessing a wireless medium according to the fourth embodiment of the present invention.

FIG. 15 is a block diagram showing a configuration of a wireless device according to Embodiment 8 of the present invention.

FIG. 16 is a sequence diagram of an authentication process performed between a center station and a communication station according to the eighth embodiment of the present invention.

FIG. 17 is a block diagram showing a configuration of a wireless device according to Embodiment 9 of the present invention.

FIG. 18 is an explanatory diagram showing an access method in a conventional example.

FIG. 19 is an explanatory diagram showing an access cycle in a conventional example.

[Explanation of symbols]

101, 601, 801 Beacon period determining unit 1001, 1201, 1301 Beacon period determining unit 102, 402, 602, 802 Residual time calculating unit 1002, 1202, 1302 Residual time calculating unit 103, 403, 603, 803 Transmission permission / inhibition determining unit 1003 1203, 1303 Transmission permission / non-permission determination unit 401 Beacon period extraction unit 604, 1013, 1213, 1313 Transmission data division unit 809, 1009 Switching unit 810, 1010 TDMA calculation unit 1209, 1309, 1505, 1705 Switch 1211, 1311, 1507, 1707 Non-fixed period mode processing unit 1212, 1312, 1506, 1706 Fixed period mode processing unit 1314 Beacon monitoring unit 1315, 1502, 1702 Mode switching unit 1503 Authentication control unit 1316, 15 4,1704 mode selection unit 1703 preamble verification unit 1711 comparison table

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroshi Doi 3-10-1, Higashi-Mita, Tama-ku, Kawasaki-shi, Kanagawa Prefecture Inside Matsushita Giken Co., Ltd. (72) Taisuke Matsumoto 3-chome, Higashi-Mita, Tama-ku, Kawasaki-shi, Kanagawa No. 10 No. 1 Matsushita Giken Co., Ltd. F term (reference) 5K028 AA06 AA11 BB04 CC02 EE07 HH02 LL41 LL43 MM04 MM08 RR00 5K033 AA01 AA04 BA13 CA08 CA11 CC01 DA17

Claims (8)

[Claims] A beacon period determining unit that estimates a period of a beacon; a remaining time calculating unit that counts time until a next beacon is received based on the period of the beacon estimated by the beacon period determining unit; A transmission permission / inhibition determination unit that determines whether data transmission is completed within the time calculated by the remaining time calculation unit and determines to perform a transmission right acquisition trial only when it is determined to be completed. A wireless communication device characterized by the following. 2. A beacon period determining unit for estimating a beacon period, a remaining time calculating unit for counting a time until a next beacon is received based on the beacon period estimated by the beacon period determining unit, A transmission enable / disable determining unit that determines whether or not data transmission is completed within the time calculated by the remaining time calculating unit; if the transmission enable / disable determining unit determines that the transmission is not completed, transmission is possible until the next beacon reception What is claimed is: 1. A wireless communication apparatus comprising: a transmission data division unit that divides transmission data into a large amount of data. 3. A beacon period determining unit for estimating a period of a beacon and a next beacon based on a period of the beacon estimated by the beacon period determining unit when communication of isochronous data and asynchronous data is performed alternately. A remaining time calculation unit that counts the time until the reception of the TDMA, a TDMA calculation unit that determines the lapse of the isochronous data communication period from the beacon, and that the isochronous data communication period has elapsed from the TDMA calculation unit. After the information is obtained, it is determined whether or not the transmission of the asynchronous data is completed within the time calculated by the remaining time calculation unit, and only when it is determined that the transmission is completed, the transmission permission is determined to be performed. A wireless communication device comprising a determining unit. 4. A beacon period determining unit for estimating a beacon period when communication of isochronous data and asynchronous data is performed alternately, and a next beacon based on a beacon period estimated by the beacon period determining unit. A remaining time calculation unit that counts the time until the reception of the TDMA, a TDMA calculation unit that determines the lapse of the isochronous data communication period from the beacon, and that the isochronous data communication period has elapsed from the TDMA calculation unit. After obtaining the information, the transmission permission / inhibition determining unit that determines whether or not the transmission of the asynchronous data is completed within the time calculated by the remaining time calculation unit, and when the transmission permission / inhibition determination unit determines that the transmission is not completed, A wireless communication device comprising: a transmission data division unit that divides transmission data into an amount of data that can be transmitted before a beacon is received. 5. A fixed-period mode processing unit for controlling data transmission so as not to hinder transmission of a beacon, a non-fixed-period mode processing unit for controlling signal transmission without considering a beacon period, A wireless communication device comprising a manual switch for switching between a fixed cycle mode processing unit and the non-fixed cycle mode processing unit. 6. The fixed-cycle mode processing unit and the non-fixed-cycle mode processing unit automatically determine whether the rising edge of the beacon is detected at the same time interval by the switch according to claim 5. The wireless communication device according to claim 5, wherein the wireless communication device is a mode switching unit for switching. 7. The mode switching section according to claim 6, wherein the mode switching section automatically switches between a fixed cycle mode processing section and a non-fixed cycle mode processing section based on operation mode information transmitted from the center station. The wireless communication device according to claim 6. 8. The fixed period mode processing unit and the non-fixed period mode processing unit automatically detect the operation mode information added to the received data and compare the tables with each other. The wireless communication device according to claim 6, wherein the switching is performed.